Hibernate persisting transient object to database How it behaves?.
It is not appropriate to save an object that has already been persisted. Equally, it is not
appropriate to update a transient object. If it is impossible or inconvenient to determine the
state of the object from your application code, you may use the saveOrUpdate() method.
When we have a persistent object in Hibernate,
that object represents both an instance of a class in a particular Java virtual machine (JVM)
and a row (or rows) in a database table (or tables).
Requesting a persistent object again from the same Hibernate session returns the same
Java instance of a class, which means that you can compare the objects using the standard Java
== equality syntax. If, however, you request a persistent object from more than one Hibernate
session, Hibernate will provide distinct instances from each session, and the == operator will
return false if you compare these object instances.
It is not appropriate to save an object that has already been persisted. Equally, it is not
appropriate to update a transient object. If it is impossible or inconvenient to determine the
state of the object from your application code, you may use the saveOrUpdate() method.
When we have a persistent object in Hibernate,
that object represents both an instance of a class in a particular Java virtual machine (JVM)
and a row (or rows) in a database table (or tables).
Requesting a persistent object again from the same Hibernate session returns the same
Java instance of a class, which means that you can compare the objects using the standard Java
== equality syntax. If, however, you request a persistent object from more than one Hibernate
session, Hibernate will provide distinct instances from each session, and the == operator will
return false if you compare these object instances.
No comments:
Post a Comment